CN1819304A - Method of manufacturing a light-emitting element, light-emitting element, display device and electronic equipment - Google Patents

Abstract

Provided are a method for manufacturing a light-emitting element, a light-emitting element, a display device, and an electronic instrument. A light-emitting element (1) is a light-emitting layer (5) inserted between an anode (3) and a cathode (6), and a hole-transporting layer (4) in contact with the light-emitting layer (5) and composed of an organic polymer as a main material. ) constituted. This light-emitting element (1) has the first step of performing an affinity-improving treatment for improving the affinity with an organic polymer on the surface side of the anode (3) on which the hole transport layer (4) is formed, to the anode ( 3) A liquid material containing the constituting material of the light-emitting layer (5), an organic polymer, and a liquid medium is supplied to the formation surface side of the hole transport layer (4) to form a liquid film, and the liquid is removed from the liquid film. While separating the organic polymer on the anode (3) side and the constituent materials of the light emitting layer (5) on the cathode (6) side, the hole transport layer (4) and the light emitting layer (5) are formed together. Second process.

Description

Manufacturing method of light-emitting element, light-emitting element, display device, and electronic device

technical field

The present invention relates to a manufacturing method of a light emitting element, a light emitting element, a display device and an electronic instrument.

Background technique

An organic electroluminescent element (hereinafter referred to as an "organic EL element") in which at least one light-emitting organic layer (organic electroluminescent layer) is sandwiched between a cathode and an anode can be larger than an inorganic EL element. By lowering the applied voltage significantly, it is possible to manufacture a device with various luminous colors (for example, see Non-Patent Documents 1 to 3 and Patent Documents 1 to 3).

Currently, in order to obtain higher-performance organic EL elements, various device structures have been proposed including development and improvement of materials, and active research is being conducted.

Furthermore, regarding such organic EL elements, elements with various light emission colors, elements with high luminance and high efficiency have been developed, and various practical applications such as pixels for display devices and light sources have been studied.

In addition, various studies are being conducted to further improve the luminous efficiency for practical use.

[Non-Patent Document 1] Appl. Phys. Lett.51(12), 1987, 9.21, p913

[Non-Patent Document 2] Appl. Phys. Lett. 71(1), 1997, 7.7, p34

[Non-Patent Document 3] Nature357, 4471992

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 10-153967

[Patent Document 2] Japanese Unexamined Patent Publication No. 10-12377

[Patent Document 3] Japanese Unexamined Patent Publication No. 11-40358

Contents of the invention

An object of the present invention is to provide a method for manufacturing a light-emitting element capable of producing a light-emitting element with excellent luminous efficiency, a light-emitting element manufactured by the light-emitting element manufacturing method, and a highly reliable display device and electronic device including the light-emitting element.

The objects of the present invention can be achieved by the following inventions.

The method for manufacturing a light-emitting element of the present invention is to insert a light-emitting layer and a carrier transport layer in contact with the light-emitting layer and composed of an organic polymer as a main material between a pair of electrodes to manufacture a light-emitting element. The manufacturing method is characterized by comprising: a first step and a second step, wherein

In the first step, of the pair of electrodes, an affinity improving treatment for improving affinity with the organic polymer is performed on a side where the carrier transport layer is formed on one electrode. ;

In the second step, a liquid material containing the light-emitting layer constituent material, the organic polymer, and a liquid medium is supplied to the side of the carrier transport layer forming surface of the one electrode to form a liquid a film, and while removing the liquid medium from the liquid film, the organic polymer is separated on the one electrode side, and the light-emitting layer constituting material is separated on the other electrode side, The carrier transport layer and the light emitting layer are formed together.

Thereby, the hole transport layer and the light-emitting layer can be reliably formed separately, and as a result, a light-emitting element with high luminous efficiency can be manufactured.

In the method for producing a light-emitting element of the present invention, it is preferable that the affinity-enhancing treatment in the first step is to introduce, to the formation surface side of the carrier transport layer of one electrode, a Chemical modification of the chemical structure of organic polymer compounds.

Thereby, the hole transport layer and the light emitting layer can be surely separated and formed.

In the method for manufacturing a light-emitting element of the present invention, the carrier transport layer is preferably a hole transport layer.

By employing a light-emitting element in which a carrier transport layer is used as a hole transport layer, a light-emitting element excellent in luminous efficiency can be produced.

In the method for manufacturing a light-emitting device according to the present invention, the hole transport layer has a first region mainly composed of a first organic polymer on the side of the one electrode, and has a first region mainly composed of a first organic polymer on the side of the light-emitting layer. a second region mainly composed of a second organic polymer different from the first organic polymer,

In the affinity improving treatment in the first step, it is preferable to perform a treatment to improve the affinity with the first organic polymer on the side of the light emitting layer forming surface of the one electrode. .

Thereby, the first region and the second region can be surely separated and formed.

In the method for manufacturing a light-emitting element of the present invention, in the second step, the first region and the second region are preferably formed together with the light-emitting layer by phase separation.

Thus, the first region and the second region can fully exert their respective functions, and at the same time, the adhesion of the interface can be increased, so that holes can migrate smoothly from the first region to the second region.

In the method for producing a light-emitting device of the present invention, it is preferable that the weight average molecular weight of the first organic polymer is larger than the weight average molecular weight of the second organic polymer.

Thereby, the orientation of the second region is improved, and the hole transport efficiency is further improved. On the other hand, the first region can be made in an amorphous state, making it difficult for crystal grains to be generated, so that a phenomenon in which holes move through grain boundaries can be prevented from occurring. As a result, the above-mentioned phenomenon increases with time, so that a short circuit between the anode and the light emitting layer can be prevented or suppressed. Therefore, the light-emitting element is an element excellent in both luminous efficiency and durability.

In the method for producing a light-emitting device of the present invention, the first organic polymer preferably has a weight-average molecular weight of 10,000 or more.

Accordingly, the first region can be brought into an amorphous state more reliably, and short-circuiting over time between the anode and the light-emitting layer can be further prevented or suppressed.

In the method for producing a light-emitting device of the present invention, the second organic polymer preferably has a weight-average molecular weight of 8,000 or less.

By using such a low-molecular-weight second organic polymer, the orientation of the second domain is higher, and the transport efficiency of holes in the second domain can be further improved.

In the manufacturing method of the light-emitting element of the present invention, the first organic polymer is preferably polyarylamine, fluorene-arylamine copolymer or derivatives thereof.

These substances are particularly preferable since they are materials excellent in hole injection efficiency.

In the manufacturing method of the light-emitting element of the present invention, the second organic polymer is preferably polyfluorene, fluorene-bithiophene copolymer or derivatives thereof.

These substances are particularly preferable because of their excellent hole transport ability.

In the method for manufacturing a light-emitting element of the present invention, the light-emitting layer is preferably composed mainly of a composite material of an inorganic semiconductor material and a light-emitting material.

In this way, the durability of the light-emitting layer can be further improved, and the life of the light-emitting element can be further extended.

In the method for manufacturing a light-emitting element of the present invention, the composite material is preferably formed by covering at least a part of the inorganic semiconductor material with the light-emitting material.

In this way, the contact area between the hole transport layer and the light-emitting material can be larger, and the size of light emission can be further expanded.

In the method for producing a light-emitting element of the present invention, the inorganic semiconductor material is preferably mainly composed of metal oxides.

Inorganic semiconductor materials mainly composed of metal oxides are preferable because of their high durability and electron transport capability.

In the method for producing a light-emitting element of the present invention, the metal oxide preferably contains zirconia as a main component.

Inorganic semiconductor materials mainly composed of zirconia are particularly preferable because of their high durability and electron transport capability.

In the method for producing a light-emitting element of the present invention, the inorganic semiconductor material is preferably granular.

Thereby, the contact area between the light-emitting layer (light-emitting material) and the hole transport layer is further increased, and the effect obtained by the above-mentioned increase in the contact area can be exhibited more remarkably.

In the method for producing a light-emitting device of the present invention, the granular inorganic semiconductor material preferably has an average particle diameter of 0.5 to 10 nanometers (nm).

In this way, a sufficient contact area between the light emitting layer and the hole transport layer can be ensured.

In the method for producing a light-emitting element of the present invention, the light-emitting material is preferably mainly composed of a metal complex.

Light-emitting materials mainly composed of metal complexes are preferable because of their high durability and high luminous efficiency.

In the method for producing a light-emitting device of the present invention, the metal complex preferably contains iridium as a central ion as a main component.

A light-emitting material mainly composed of an iridium complex is particularly preferable because of its high durability and high light-emitting efficiency.

In the method for producing a light-emitting element of the present invention, in the second step, the removal of the liquid solvent is preferably performed in an atmosphere containing a vapor of a polar solvent.

In this way, the complex can be more reliably concentrated on the other electrode side in the liquid coating.

In the method for producing a light-emitting element of the present invention, in the second step, the removal of the liquid solvent is preferably performed while causing convection in the liquid coating.

Accordingly, it is possible to more reliably concentrate the complex on the other electrode side in the liquid coating.

In the method of manufacturing a light-emitting element of the present invention, it is preferable that the convection is generated by heating the liquid film.

If the heating method is adopted, the convection in the liquid coating can be adjusted relatively easily.

The light-emitting element of the present invention is characterized by being produced by the method for producing a light-emitting element of the present invention.

In this way, a light-emitting element excellent in luminous efficiency can be obtained.

The display device of the present invention is characterized by including the light-emitting element of the present invention.

In this way, a highly reliable display device can be obtained.

An electronic device of the present invention is characterized in that it includes the display device of the present invention.

Thus, a highly reliable electronic device can be obtained.

Description of drawings

FIG. 1 is a longitudinal sectional view schematically showing an embodiment of a light emitting element of the present invention.

Fig. 2 is a diagram schematically showing the vicinity of the interface of each part (layer) of the light emitting element shown in Fig. 1 .

FIG. 3 is a further enlarged view of FIG. 2 .

4 is a longitudinal sectional view showing an embodiment of a display device using the display device of the present invention.

Fig. 5 is a perspective view showing the configuration of a portable (or notebook type) personal computer to which the electronic device of the present invention is applied.

Fig. 6 is a perspective view showing the configuration of a mobile phone (including a PHS) employing the electronic device of the present invention.

Fig. 7 is a perspective view showing the configuration of a digital camera employing the electronic device of the present invention. In the figure: 1...light-emitting element, 2...substrate, 3...anode, 4...hole transport layer, 41...first region, 42...second region, 5...light-emitting layer, 51...inorganic semiconductor particles, 52...luminescent material , 6...cathode, 7...sealing member, 10...display device, 20 substrate, 21...substrate,...22...circuit part, 23...protective layer, 24...driving TFT, 241...semiconductor layer, 242...gate insulating layer, 243...gate electrode, 244...source electrode, 245...drain electrode, 25...first interlayer insulating layer, 26...second interlayer insulating layer, 27...wiring, 31...first partition wall, 32...second partition wall Part, 1100...personal computer, 1102...keyboard, 1104...main part, 1106...display unit, 1200...mobile phone, 1202...operating buttons, 1204...receiving port, 1206...sending port, 1300...digital camera, 1302 ...housing (main body), 1304...light receiving unit, 1306...shutter button, 1308...circuit board, 1312...video signal output terminal, 1314...input/output terminal for data communication, 1430...TV monitor, 1440...personal computer.

Detailed ways

Hereinafter, best embodiments of a method for manufacturing a light-emitting element, a light-emitting element, a display device, and an electronic device of the present invention will be described with reference to the drawings.

1 is a diagram schematically showing a longitudinal section of an embodiment of a light-emitting element of the present invention, FIG. 2 is a diagram schematically showing the vicinity of the interface of each part (layer) of the light-emitting element shown in FIG. 1 , and FIG. 3 shows a further enlarged view of FIG. 2 picture. In addition, in the following description, the upper side of FIGS. 1 to 3 is called "upper" and the lower side is called "lower" for convenience of explanation.

The light-emitting element (electroluminescence element) 1 shown in FIG. The transport layer (carrier transport layer) 4 and the light-emitting layer 5 on the cathode 6 side are formed, and are provided on the substrate 2 . Further, the anode 3 , the hole transport layer 4 , the light emitting layer 5 and the cathode 6 are sealed with the sealing material 7 .

The substrate 2 serves as a support for the light emitting element 1 . Since the light-emitting element 1 of this embodiment is configured to take out light from the substrate 2 side (bottom emission type), the substrate 2 and the anode 3 are made substantially transparent (colorless transparent, colored transparent, or translucent) respectively. .

Examples of the constituent material of the substrate 2 include polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethylmethacrylate , resin materials such as polycarbonate and polyarylate, glass such as quartz glass and soda glass, etc., among these substances, one kind or a combination of two or more can be used.

The average thickness of the substrate 2 is not particularly limited, but is preferably about 0.1 to 30 mm, more preferably about 0.1 to 10 mm.

In addition, when the light-emitting element 1 has a configuration in which light is taken out from the side opposite to the substrate 2 (top emission type), the substrate 2 can be either a transparent substrate or an opaque substrate.

Examples of opaque substrates include substrates made of ceramic materials such as alumina, metal substrates such as stainless steel with an oxide film (insulating film) formed on the surface, and substrates made of resin materials.

The anode 3 is an electrode for injecting holes into the hole transport layer 4 described later. The constituent material of the anode 3 is preferably a material with a large work function and excellent electrical conductivity.

Examples of the constituent material of the anode 3 include oxides such as ITO (indium tin oxide), IZO (indium zinc oxide), In ₃ O ₃ , SnO ₂ , SnO ₂ containing Sb, ZnO containing Al, Au , Pt, Ag, Cu, or alloys containing these, etc., one or more of these substances can be used in combination.

The average thickness of the anode 3 is not particularly limited, but is preferably about 10 to 200 nm, more preferably about 50 to 150 nm.

On the other hand, the cathode 6 is an electrode for injecting electrons into the light-emitting layer 5 described later. The constituent material of the cathode 6 is preferably a material having a small work function.

Examples of the constituent material of the cathode 6 include Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, Yb, Ag, Cu, Al, Cs, Rb, or alloys containing these, etc. Among the substances, one kind or a combination of two or more kinds can be used.

Especially when an alloy is used as the constituent material of the cathode 6, an alloy containing stable metal elements such as Ag, Cu, and Al is preferably used, specifically, an alloy of MgAg, AlLi, CuLi, etc. is preferably used. By using such an alloy as a constituent material of the cathode, the electron injection efficiency and stability of the cathode 6 can be improved.

The average thickness of the cathode 6 is not particularly limited, but is preferably about 100 to 10000 nanometers (nm), more preferably about 200 to 500 nm.

In addition, since the light-emitting element 1 of this embodiment is a bottom emission type, there is no particular requirement on the light-transmitting properties of the cathode 6 .

The hole transport layer 4 is a layer having a function of transporting holes injected from the anode 3 to the light emitting layer 5 . This hole transport layer 4 is mainly composed of an organic polymer.

Various p-type semiconductor materials can be used as this organic polymer, such as polyarylamine, fluorene-arylamine copolymer, fluorene-bithiophene copolymer, poly(N-vinylcarbazole), polyethylene Pyrene, polyvinyl anthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylene vinylene), polythienylene vinylene, pyrene formaldehyde resin, ethyl carbazole Formaldehyde resin or its derivatives, etc., can be used alone or in combination of two or more of these substances.

Furthermore, the above-mentioned compounds can also be used in admixture with other compounds. As an example, the mixture containing polythiophene includes poly(3,4-ethylenedioxythiophene/styrenesulfonic acid) (PEDOT/PSS) and the like.

Furthermore, the hole transport layer 4 of the present embodiment has a first region 41 in contact with the anode 3 and a second region 42 in contact with the light emitting layer 5 as shown in FIGS. 1 and 2 .

The first region 41 is mainly composed of a first organic polymer, and the second region 42 is mainly composed of a second organic polymer different from the first organic polymer. These regions 41, 42 can be passed through The phase separation (perpendicular phase separation) described later is formed together with the light-emitting layer.

Moreover, the first region 41 and the second region 42, as shown in FIG. 2, their interface is generally parallel to the top of the anode 3 from a macroscopic point of view. As shown in FIG. (overlapping) state.

Thus, the first region 41 and the second region 42 can fully exert their respective functions, and at the same time, the adhesion on the interface increases, and the migration of holes from the first region 41 to the second region 42 becomes smoother. .

Here, as a combination of the first organic polymer and the second organic polymer, for example, I: select one that has excellent hole injection efficiency in the first organic polymer, and select one that has strong orientation in the second organic polymer. , a combination excellent in hole transport efficiency, II: a combination in which the bandgap of the first organic polymer is larger than that of the second organic polymer, etc. are selected.

In the case of I, holes are efficiently injected from the anode 3 to the second region 42 through the first region 41, and the injected holes will be transported through the second region 42 with higher efficiency; and in the case of II, the holes Moving from the anode 3 towards the light-emitting layer 5 stepwise (smoothly), ie holes are transported more efficiently in the hole transport layer. As a result, in either case of I and II, the luminous efficiency of the light-emitting element 1 can be improved.

In the case of I, polyarylamine, fluorene-arylamine copolymer or derivatives thereof are preferably used as the first organic polymer. These substances are particularly preferably materials excellent in hole injection efficiency.

Here, a triphenylamine-based polymer represented by the following chemical formula 1 is given as an example of the polyarylamine derivative.

[chemical formula 1]

On the other hand, polyfluorene, fluorene-bithiophene copolymer or derivatives thereof are preferably used as the second organic polymer. These substances are particularly preferably those excellent in hole transport ability.

Here, a polyfluorene-based polymer represented by the following chemical formula 2 is given as an example of a polyfluorene derivative.

[chemical formula 2]

And in the case of I, the second organic polymer is preferably selected to have a lower molecular weight, and the first organic polymer preferably has a weight-average molecular weight that is larger (has a higher molecular weight) than the weight-average molecular weight of the second organic polymer. Thereby, the following effects can be obtained.

That is, the orientation of the second region 42 is improved, and the hole transport efficiency is further improved. On the other hand, the first region 41 can be made into an amorphous state, making it difficult for crystal grains to be formed, so that holes (carriers) can be prevented from moving at grain boundaries (between crystal grains). As a result, the above phenomenon increases over time, and it is possible to prevent or suppress short circuit between the anode 3 and the light emitting layer 5 . Therefore, the light-emitting element 1 will be an element excellent in both luminous efficiency and durability.

In this case, the weight average molecular weight of the first organic polymer is preferably 10,000 or more, more preferably 15,000 to 50,000. Thereby, the first region 41 can be made into an amorphous state more reliably, and short-circuiting over time between the anode 3 and the light emitting layer 5 can be more reliably prevented or suppressed.

On the other hand, the second organic polymer is preferably 8,000 or less, and more preferably about 1,500 to 5,000. By using such a low molecular weight second organic polymer, the orientation of the second region 42 is higher, and the hole transport efficiency in the second region 42 can be further improved.

Furthermore, by combining the first organic polymer and the second organic polymer having such a weight average molecular weight, the first domain 41 and the second domain 42 can be separated and formed more reliably due to the phase separation effect described later, and at the same time, More reliably, the second region 42 is formed separately from the light emitting layer 5 .

The average thickness of the hole transport layer 4 (total of the first region 41 and the second region 42 ) is not particularly limited, but is preferably about 10 to 150 nm, more preferably about 50 to 100 nm.

In addition, in the present embodiment, the structure of the hole transport layer 4 has two regions made of different organic polymers, but the hole transport layer 4 may be composed of one organic polymer as a main material.

The light emitting layer 5 is provided in contact with the hole transport layer 4 (second region 42 ). This light-emitting layer 5 receives holes from the hole-transporting layer 4 while transporting electrons injected from the cathode. The holes and electrons are then recombined near the interface of the hole transport layer 4, and the energy released during this recombination produces excitons, which will release energy (fluorescence or phosphorescence) when the excitons return to the ground state glow.

As described above, such light-emitting layer 5 forms the first region 41 and the second region 42 together due to phase separation (vertical phase separation).

Moreover, the light-emitting layer 5 and the hole transport layer 4, as shown in FIG. 2 , are generally parallel to the upper surface of the anode 3 from a macroscopic point of view. As shown in FIG. (overlapped) state.

Therefore, the contact area between the light emitting layer 5 and the hole transport layer 4 increases, and the recombination sites of electrons and holes expand. And since this recombination site exists on the part separated from the electrodes (anode 3 and cathode 6), as a result, the luminescence site will expand (the number of molecules contributing to luminescence increases). Therefore, the luminous efficiency of the light-emitting element 1 can be improved, and the lifetime can be further extended.

Moreover, since the interface between the light-emitting layer 5 and the hole transport layer 4 is uneven (flat) and has a concave-convex shape, even if the driving voltage is increased, it is possible to prevent holes and electrons from being excited and combined together, thereby preventing a sharp increase in luminous intensity. . Therefore, since the luminance can be increased stably in accordance with the driving voltage, it is possible to easily perform the control of the emission luminance of the light emitting element 1 and the tuning control of low luminance. In addition, there is an advantage that a complicated peripheral circuit for finely controlling the driving voltage is unnecessary.

The light emitting layer 5 of the present embodiment is mainly composed of a composite of inorganic semiconductor particles (particulate inorganic semiconductor material) 51 and a light emitting material 52 . In the illustrated configuration, the light emitting material 52 covers the entirety of the inorganic semiconductor particles 51 , but may also cover a part of the inorganic semiconductor particles 51 . By covering the surface of the inorganic semiconductor material particle 51 with the luminescent material 52 in this way, the contact area between the hole transport layer 4 and the luminescent material 52 can be further increased, thereby further increasing the luminescent size.

In such a light-emitting layer 5 , electrons are supplied to the light-emitting material 52 via the inorganic semiconductor particles 51 to cause the light-emitting material 52 to emit light. That is, the aggregate (aggregate) of the inorganic semiconductor particles 51 may also be called an electron transport layer.

Thus, by using an inorganic semiconductor material as a constituent material of the light emitting layer 5, the durability of the light emitting layer 5 can be further improved, and the lifetime of the light emitting element 1 can be further extended.

Examples of such inorganic semiconductor materials include metal oxides such as ZrO ₂ , TiO ₂ , TiO, Ti ₂ O ₃ , NbO, SrTiO ₃ , ZnO, SiO ₂ , Al ₂ O ₃ , SnO ₂ , ZnS, CdS Metal sulfides such as CdSe, metal selenides such as CdSe, metal or semiconductor carbides such as TiC and SiC, semiconductor nitrides such as Si ₃ N ₄ , B ₄ N, and BN, etc., these substances can use one or two More than one combination (such as mixture, solid solution, etc.) used.

Among these materials, the inorganic semiconductor material is preferably composed mainly of metal oxides, and among metal oxides, ZrO ₂ (zirconium oxide) is particularly preferable as a main component. Inorganic semiconductor materials mainly composed of metal oxides (particularly ZrO ₂ ) are preferable because of their high durability and electron transport capability.

Furthermore, as in this embodiment, by making the inorganic semiconductor material granular, the contact area between the light-emitting layer 5 (light-emitting material 52) and the hole transport layer 4 is further increased, and the effect obtained due to the increase in the above-mentioned contact area can be exerted. more prominently.

In this case, the average particle size of the inorganic semiconductor particles (particulate inorganic semiconductor material) 51 is preferably about 0.5 to 10 nm, more preferably about 1 to 7 nm. Thereby, a sufficient contact area between the light-emitting layer 5 and the hole transport layer 4 can be ensured, and the above-mentioned effects can be further enhanced.

Furthermore, as the luminescent material 52, for example, a tricoordinated iridium complex having a ligand of 2,2'-bipyridine-4,4'-dicarboxylic acid represented by the following chemical formula 3, a tri( 2-Phenylpyridine) iridium (Ir(ppy) ₃ ), 8-hydroxyquinoline aluminum (Alq ₃ ), tris(4-methyl-8 quinolate) aluminum (III) (Almq ₃ ), 8-hydroxyquinolate Zinc quinoline (Znq ₂ ), (1,10-phenanthroline)-tris-(4,4,4-trifluoro-1-(2-thienyl)-butane-1,3-di Formate (dionato)) europium (III) (Eu(TTA) ₃ (Phen)), 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum ( Various metal coordination compounds such as porphyrin platinum (II), benzene compounds such as distyrylbenzene (DSB) and diaminodistyrylbenzene (DADSB), naphthalene compounds such as naphthalene and Nile red, phenanthrene, etc. Phenanthrene compounds, 1,2-triphenylene, 6-nitro-1,2-triphenylene and other 1,2-triphenylene compounds, perylene (ie perylene), N, N-di( Perylene compounds such as 2,5-di-tert-butylphenyl)-3,4,9,10-perylene-dicarboxamide (BPPC), coronene compounds such as coronene, anthracene such as anthracene and distyryl anthracene Pyrene-based compounds, pyrene-based compounds such as pyrene, pyran-based compounds such as 4-(diaminomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM), Acridine-based compounds such as acridine, stilbene (i.e. 1,2-stilbene, etc.) 1,2-stilbene-based compounds, 2,5-dibenzoxazolethiophene and other thiophene-based compounds, benzoxazole, etc. Benzixazole-based compounds, benzimidazole-based compounds such as benzimidazole, benzothiazole-based compounds such as 2,2'-(p-phenylene vinylene)-dibenzothiazole, diphenylene (1,4- Butadiene-based compounds such as diphenyl-1,3-butadiene), tetraphenylbutadiene and other butadiene-based compounds, naphthalimide-based compounds such as naphthalimide-based compounds, coumarin-based compounds such as coumarin, perinone ( Perinone-based compounds such as perinon), oxadiazole-based compounds such as oxadiazole, aldehyde azine-based compounds, cyclic compounds such as 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP) Pentadiene-based compounds, quinacridone-based compounds such as 2,3-quinacridone and quinacridone red, pyridine-based compounds such as pyrrolopyridine and thiadiazolopyridine, 2,2',7,7'-tetra Spiro compounds such as phenyl-9,9'-spirobifluorene, metal or metal-free phthalocyanine compounds such as phthalocyanine (H ₂ PC) and copper phthalocyanine, fluorene series compounds such as fluorene, etc. Use one or two or more in combination.

[chemical formula 3]

Among these substances, the luminescent material 52 is preferably mainly composed of metal complexes, and among the metal complexes, it is more preferable that the main component is a complex containing iridium as a central metal (iridium complex). The light-emitting material 52 mainly composed of a metal complex (particularly an iridium complex) is preferable because of its high durability and high luminous efficiency.

The average thickness of the light-emitting layer 5 is not particularly limited, but is preferably about 1 to 100 nm, and more preferably about 20 to 50 nm.

Wherein, for the light-emitting layer 5, as materials that contribute to electron transport, in addition to using organic semiconductor materials instead of inorganic semiconductor materials, materials that contribute to electron transport can also be omitted, and the above-mentioned light-emitting materials (low molecular light emitting material) 52 is the main material.

Moreover, the light-emitting layer 5 can also be composed of a polymer light-emitting material as a main material. In this case, an organic polymer is used as the constituent material of the hole transport layer 4, and by appropriately selecting the light emitting material and the organic polymer, the light emitting layer 5 and the hole transport layer 4 can be formed together by phase separation described later. In this case, it is decided to select, for example, an organic polymer whose weight average molecular weight is smaller than that of the light emitting material.

Examples of polymer light-emitting materials include polyacetylene-based compounds such as trans polyacetylene, cis polyacetylene, poly(diphenylacetylene) (PDPA), poly(alkyl, phenylacetylene) (PAPA), polyacetylene (p-phenylene vinylene) (PPV), poly(2,5-dialkoxy-p-phenylene vinylene) (RO-PPV), cyano-substituted poly(phenylene vinylene) (CN-PPV) , poly(2-methyloctylsilyl-p-phenylene vinylene) (DMOS-PPV), poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV) and other poly-p-phenylene vinylene compounds, poly(3-alkylthiophene) (PAT), poly(oxypropylene) triol (POPT) and other polythiophene compounds, poly(9,9-di Alkylfluorene) (PDAF), poly(dioctylfluorenyl-o-benzothiadiazole) (F8BT), α,ω-bis[N,N'-bis(methylphenyl)aminophenyl]- Poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl](PF2/6am4), poly(9,9-dioctyl-2,7-divinylidenefluorenyl)- Ortho (anthracene-9,10-diyl) and other fluorene compounds, poly (p-phenylene) (PPP), poly (1,5-dialkoxy-p-phenylene) (RO-PPP) and other poly-p-phenylene Brain compounds, poly(N-vinylcarbazole) (PVK) and other carbazole compounds, poly(methylphenylsilane) (PMPS), poly(naphthylphenylsilane) (PNPS), poly(biphenyl Phenylphenylsilane) (PBPS) and other polysilane compounds.

The sealing member 7 is provided so as to cover the anode 3, the hole transport layer 4, the light-emitting layer 5, and the cathode 6 to hermetically seal them, and has a function of blocking oxygen or moisture. By providing the sealing member 7, the reliability of the light-emitting element 1 can be improved, and there is an effect of preventing deterioration and deterioration (improved durability).

Examples of the constituent material of the sealing member 7 include Al, Au, Cr, Nb, Ta, Ti, or alloys containing them, silicon oxide, various resin materials, and the like. Moreover, in the case of using a conductive material as the constituent material of the sealing member 7, in order to prevent a short circuit, it is preferable to provide insulation between the sealing member 7 and the anode 3, the hole transport layer 4, the light emitting layer 5, and the cathode 6 if necessary. membrane.

Further, the sealing member 7 may be made to face the substrate 2 in the form of a flat plate, and the sealing member 7 may be sealed therebetween with a sealing material such as a thermosetting resin, for example.

Such a light-emitting element 1 can be produced, for example, as follows.

[1] First, the substrate 2 is prepared, and the anode 3 is formed on the substrate 2 .

Anode 3, for example, can adopt chemical vapor deposition methods (CVD) such as plasma CVD, thermal CVD, and laser CVD, dry coating methods such as vacuum evaporation, sputtering, and ion plating, and wet plating methods such as electroplating, immersion plating, and electroless plating. Formed by metal spraying method, sol-gel method, MOD method, metal foil welding method, etc.

[2] Next, in order to improve the affinity with the first organic polymer, an affinity-enhancing treatment is performed on the upper surface of the anode 3 (the side on which the hole-transporting layer 4 is formed) (first step).

Thereby, in the next step [3], the first organic polymer can be more reliably concentrated on the anode 3 side (lower side) in the liquid film, so that the first region 41 and the second region 42 can be separated and formed reliably. and luminescent layer 5.

As such an affinity-enhancing treatment, for example, a chemical modification treatment of introducing a chemical structure (structural unit) containing a part of the compound constituting the first organic polymer, or the case where the first organic polymer exhibits hydrophilicity The following hydrophilic treatment, but the former is preferred. This can further enhance the above-mentioned effects.

For example, in the case where the first organic polymer has a triphenylamine skeleton (structure), a chemical modification treatment is performed so as to introduce, on the surface of the anode 3, a terminal having an amino group, triphenylamine (arylamine), phenyl group, benzyl group, etc. the alkyl chain.

In addition, as the treatment agent (reagent) for chemical modification treatment, for example, when the anode 3 is composed of metal oxide as the main material, one end has an atomic group to be introduced, and the other end has trimethylsilane, Compounds (coupling agents) such as methylsilane and trichlorosilane, and when the anode 3 is composed of Au, Pt, etc. as the main material, one end has an atomic group to be introduced, and the other end has a thiol group. etc. compounds.

[3] Next, the hole transport layer 4 (the first region 41 and the second region 42 ) and the light-emitting layer 5 are formed together on the first region 1 by the phase separation method (second step). This process can be performed as follows.

First, the first organic polymer and the second organic polymer are dissolved in a solvent (liquid solvent), and then the composite of the inorganic semiconductor particles 51 and the light emitting material 52 is dispersed in the solution to prepare a liquid material.

Examples of solvents include inorganic solvents such as nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, ethylene carbonate, methyl ethyl ketone (MEK), acetone, diethyl ketone, Methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), cyclohexanone and other ketone solvents, methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol (DEG), glycerin and other alcohols Solvents, diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anise Ether, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether (carbitol) and other ether solvents, methyl cellosolve, ethyl cellosolve, phenyl cellosolve and other cellosolves Solvents, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, etc., aromatic hydrocarbon solvents such as toluene, xylene, benzene, etc., pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone, etc. Aromatic heterocyclic compound-based solvents, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA) and other amide-based solvents, chlorobenzene, methylene chloride, chloroform, 1, 2-dichloroethane and other halogen-containing compound solvents, ethyl acetate, methyl acetate, ethyl formate and other ester solvents, dimethyl sulfoxide (DMSO), sulfolane and other sulfur-containing compound solvents, acetonitrile, propionitrile Nitrile solvents such as , acrylonitrile, organic solvents such as organic acid solvents such as formic acid, acetic acid, trichloroacetic acid, and trifluoroacetic acid, or mixed solvents containing them.

Among these solvents, non-polar solvents are especially suitable, for example, aromatic hydrocarbon solvents such as xylene, toluene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, pyridine, pyrazine, etc. , furan, pyrrole, thiophene, methylpyrrolidone and other aromatic heterocyclic compound solvents, hexane, pentane, heptane, cyclohexane and other aliphatic hydrocarbon solvents, etc. These solvents can be used alone or in combination.

Next, this liquid material is supplied to the anode 3 to form a liquid thin film.

As the supply method of such a liquid material, for example, a spin coating method, a casting method, a rotogravure method, a gravure method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, etc. , screen printing, flexographic printing, offset printing, inkjet and other coating methods. Using this coating method can relatively easily form the first region 41 .

The solvent is then removed from the liquid-like film. Once the solvent is removed, the first organic polymer and the second organic polymer will follow the order of the first organic polymer and the second organic polymer on the anode 3 side in the liquid film, and on the other hand, the composite body will be separated and solidified on the cathode 6 side to form the first region 41, the second organic polymer, and the second organic polymer. region 42 and the light-emitting layer 5 . That is, the first region 41, the second region 42, and the light emitting layer 5 may be formed together by phase separation.

At this time, by appropriately setting the type of solvent, the weight-average molecular weight of the first organic polymer, the weight-average molecular weight of the second organic polymer, the content of the first organic polymer in the liquid material, and the second organic polymer in the liquid material. The content of the substance, the content of the complex in the liquid material (constituent material of the light-emitting layer 5), the speed of removing the solvent, the atmosphere when removing the solvent, and the surface state of the lower layer of the liquid material are supplied to control the first condition. A phase-separated state of an organic polymer, a second organic polymer, and a composite.

For example, the atmosphere at the time of removing the solvent is preferably an atmosphere containing a vapor of a polar solvent. This enables the above-mentioned complexes to be more reliably concentrated on the upper side of the liquid coating. Furthermore, examples of the polar solvent include alcohols such as water, methanol, ethanol, and isopropanol.

In addition, when removing the solvent, it is preferable to carry out under the condition that convection is generated in the liquid film. This enables the above-mentioned complexes to be more reliably concentrated on the upper side of the liquid coating. In addition, in this case, since the upper surface of the anode 3 is subjected to an affinity-enhancing treatment, it is possible to prevent the accumulation of the first organic polymer on the anode 3 side from being hindered.

The convection can be performed by, for example, heating the liquid film, applying ultrasonic waves to the substrate 2, or applying ultrasonic-applied liquid droplets (liquid material), but heating is preferred. If the heating method is used, convection adjustment (control) in the liquid coating is relatively easy.

In this case, the heating temperature is preferably about B-100 to B-10°C, more preferably about B-100 to B-25°C when the boiling point of the solvent is B[°C].

[4] Further, the cathode 6 is formed on the light emitting layer 5 .

The cathode 6 can be formed by, for example, a vacuum evaporation method, a sputtering method, a metal foil welding method, or the like.

[5] Next, the sealing member 7 is covered so as to cover the anode 3 , the hole transport layer 4 , the light emitting layer 5 and the cathode 6 , and bonded to the substrate 2 .

Through the above steps, the light-emitting element 1 of the present invention can be produced.

Furthermore, on the light-emitting element 1 , any one of the anode 3 and the hole transport layer 4, between the hole transport layer 4 and the light-emitting layer 5, and at least one of the light-emitting layer 5 and the cathode 6 may be provided. target layer.

For example, an intermediate layer having a function of promoting injection of electrons into the light emitting layer 5 may be provided between the light emitting layer 5 and the cathode 6 . By providing the intermediate layer, the luminous efficiency of the light emitting element 1 is further improved. Furthermore, the intermediate layer may also function to prevent or suppress contact between the hole transport layer 4 and the cathode 6 .

The intermediate layer is preferably composed of a material having a higher conduction band energy order (lower end potential) than the constituent material of the light emitting layer 5 (inorganic semiconductor material in this embodiment). Thereby, electrons can be moved stepwise (smoothly) from the cathode 6 to the light emitting layer 5 (light emitting material), that is, electrons can be efficiently injected into the light emitting layer 5 . As a result, the luminous efficiency of the light emitting element 1 will be further improved.

The material constituting such an intermediate layer is not particularly limited as long as it satisfies the above conditions. For example, organic or inorganic semiconductor materials alone, or complexes of organic or inorganic semiconductor materials and compounds having electron-withdrawing groups, etc. can be used.

In addition, when a granular substance (semiconductor material particle) is used as the semiconductor material, at least a part of the semiconductor material particle is covered (modified) with a compound having an electron-withdrawing group as the composite body.

Moreover, by selecting the type of compound with such an electron-withdrawing group, the energy order of the conduction band of the semiconductor material can be adjusted.

As a compound having such an electron-withdrawing group, for example, CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ (CH ₃ ) ₂ Si(CH ₂ ) ₅ SiCl ₃ :F17, CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ (CH ₃ ) ₂ Si(CH ₂ ) ₉ SiCl ₃ :F9, CF ₃ (CH ₂ ) ₂ (CH ₃ ) ₂ Si(CH ₂ ) ₁₂ SiCl ₃ :F3 and other fluorocarbon silane coupling compounds, etc. .

The method of compounding (coating) such a compound with a semiconductor material includes, for example, vaporizing the above-mentioned compound and exposing the semiconductor material to the vapor (gas-phase method), and mixing a liquid containing the above-mentioned compound with the semiconductor material. The method of material contact (liquid phase method), etc.

The average thickness of such an intermediate layer is preferably about 1 to 50 nm, more preferably about 5 to 30 nm.

In this embodiment, the carrier transport layer is described as a representative case of a hole transport layer, but the carrier transport layer may also be an electron transport layer.

In this case, examples of organic polymers that can be used in the electron transport layer include oxadiazole-based polymers, triazole-based polymers, and the like.

Such a light emitting element 1 can be used as a light source or the like, for example. Furthermore, a display device (display device of the present invention) can be configured by arranging a plurality of light emitting elements in a matrix.

In addition, there is no particular limitation on the driving method of the display device, and any method of an active matrix type or a passive matrix type may be used.

An example of a display device using the display device of the present invention will be described below.

4 is a longitudinal sectional view showing an embodiment of a display device using the display device of the present invention.

The display device 10 shown in FIG. 4 is composed of a base 20 and a plurality of light emitting elements 1 provided on the substrate 20 .

The base body 20 has a substrate 21 and a circuit portion 22 formed on the substrate 21 .

The circuit portion 22 has a protective layer 23 formed, for example, of a silicon oxide layer formed on the substrate 21, a driving TFT (switching element) 24 formed on the protective layer 23, a first interlayer insulating layer 25, and a second interlayer insulating layer 25. Layer 26.

The driving TFT 24 has a semiconductor layer 241 made of silicon, a gate insulating layer 242 formed on the semiconductor layer 241 , a gate electrode 243 formed on the gate insulating layer 242 , a source electrode 244 , and a drain electrode 245 .

The light emitting element 1 is provided on such a circuit portion 22 corresponding to each driving TFT 24 . Further, the adjacent light emitting elements 1 are partitioned by the first partition wall portion 31 and the second partition wall portion 32 .

In the present embodiment, the anode 3 of each light emitting element 1 constitutes a pixel electrode, and is electrically connected to the drain electrode 245 of each driving TFT 24 through the wiring 27 . Also, the cathode 6 of each light emitting element 1 is used as a common electrode.

Then, a sealing member (not shown) is bonded to the base body 20 so as to cover the light emitting elements 1 , and each light emitting element 1 is sealed.

The display device 10 can perform monochrome display, or can perform color display by selecting the light-emitting material for each light-emitting element.

Such a display device 10 (display device of the present invention) can be installed in various electronic devices.

Fig. 5 is a perspective view showing the configuration of a mobile (or notebook) personal computer using the electronic device of the present invention.

In this figure, a personal computer 1100 is composed of a main body 1104 including a keyboard 1102 and a display unit 1106 including a display. The display unit 1106 is rotatably supported by the main body 1104 via a hinge member.

In such a personal computer 1100 , the display unit including the display unit 1106 is constituted by the above-mentioned display device 10 .

Fig. 6 is a perspective view showing the configuration of a mobile phone (including a PHS) employing the electronic device of the present invention.

In this figure, a mobile phone 1200 includes a plurality of operation buttons 1202, a receiver port 1204, a speaker port 1206, and a display unit.

In mobile phone 1200, such a display unit is constituted by display device 10 described above.

Fig. 7 is a perspective view showing the configuration of a digital camera employing the electronic device of the present invention. Also, in this figure, connections to external devices are simply shown.

Here, a normal camera uses the light image of the object to expose the silver salt photographic film, while the digital camera 1300 uses an imaging element such as a CCD (charge-coupled device) to convert the light image of the object through photoelectric conversion to generate an imaging signal. (image signal).

In the digital camera 1300, a display unit is provided on the back surface of a housing (main body) 1302, and is configured to display based on a signal captured by the CCD and function as a viewfinder that displays a subject as an electronic image.

In the digital camera 1300 , such a display unit is constituted by the above-mentioned display device 10 .

A circuit board 1308 is provided inside the housing. Such a circuit board 1308 is used as a memory capable of storing (memorizing) imaging signals.

Further, a light receiving unit 1304 including an optical lens (photographic optical system), a CCD, and the like is provided on the front side (rear side in the illustrated configuration) of the casing 1302 .

After the photographer confirms the image of the subject displayed on the display unit, once he presses the shutter button 1306, the CCD imaging signal at that time can be sent to the memory of the circuit board 1308 for storage.

In addition, in the digital camera 1300 , a video signal output terminal 1312 and an input/output terminal 1314 for data communication are provided on the side surface of the casing 1302 . Furthermore, as shown in the drawing, a television monitor 1430 is connected to a video signal output terminal 1312, and a personal computer 1440 is connected to a data communication input/output terminal 1314 as necessary. In addition, it is configured to output the imaging signal stored in the memory of the circuit board 1308 to the television monitor 1430 and the personal computer 1440 through a predetermined operation.

In addition, the electronic equipment of the present invention, in addition to the personal computer (mobile personal computer) in FIG. 5, the mobile phone in FIG. 6, and the digital camera in FIG. type, monitor direct-view video tape recorders, notebook personal computers, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game machines, word processors, workstations, video Telephones, self-defense monitors, electronic glasses, POS terminals, devices with touch screens (such as ATMs and ticket vending machines in financial institutions), medical devices (such as electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram display devices, Ultrasonic diagnostic devices, display devices for endoscopes), fish detectors, various measuring instruments, measuring instruments (such as measuring instruments for vehicles, airplanes, and ships), flight simulators, various other monitors, projectors, etc. display device, etc.

Although the manufacturing method of the light-emitting element, the light-emitting element, the display device, and the electronic device of the present invention have been described above based on the illustrated embodiments, the present invention is not limited thereto.

【Example】

Specific examples of the present invention will be described below.

(Example 1)

A light-emitting element was produced in the following manner, and its luminous efficiency and durability (lifetime) were evaluated.

[Sample No. 1A]

(1A) First, a transparent glass substrate with an average thickness of 0.5 mm was prepared.

(2A) Then, an ITO electrode (anode) having an average thickness of 100 nm was formed on this substrate by sputtering.

(3A) Further, an ethanol solution of 0.1% by weight of NH ₂ (CH ₂ ) ₅ SiCl ₃ (silane coupling agent) was coated on this ITO electrode by the spin coating method (2000 rpm), and then dried.

(4A) Next, the polyaniline-based polymer (weight-average molecular weight: 40000) shown in the above chemical formula 1 is used as the first organic polymer, and the polyfluorene-based polymer (weight-average molecular weight: 5000) shown in the above chemical formula 2 is used as the first organic polymer. The second organic polymer and the zirconia particles coated with the iridium complex compound were used as the constituting material of the light-emitting layer, respectively added to xylene to prepare a liquid material.

In addition, the polyaniline-based polymer content was 0.5% by weight, the polyfluorene-based polymer content was 0.5% by weight, and the content of zirconia particles coated with an iridium complex was 2.0% by weight.

In addition, the average particle size of the zirconia particles is 5 nanometers.

In addition, as the iridium complex, a tricoordinate iridium complex having a ligand of 2,2'-bipyridine-4,4'-dicarboxylic acid represented by the above chemical formula 3 was used.

Furthermore, this liquid material was applied on the ITO electrode by the spin coating method (2000 rpm), and then dried. This forms the hole transport layer (the first region and the second region) and the light emitting layer by phase separation.

In addition, the drying condition of a liquid material is 50 degreeC in isopropanol atmosphere. Here, this temperature is the temperature at which convection occurs in the liquid-like coating.

(5A) Next, zirconia particles coated with F17 (fluorocarbon-based silane coupling agent compound) were dispersed in isopropanol as an intermediate layer constituent material to prepare a dispersion liquid.

Then, this dispersion liquid was applied on the light-emitting layer by a spin coating method (2000 rpm), followed by drying. This formed an intermediate layer with an average thickness of 10 nm.

In addition, the average particle diameter of the zirconia particles was 5 nanometers.

(6A) Next, an AlLi electrode (cathode) having an average thickness of 300 nm was formed on the intermediate layer by a vacuum evaporation method.

Next, a protective film (sealing member) made of polycarbonate was applied to cover each formed layer, and after being fixed and sealed with an ultraviolet curable resin, a light-emitting element was produced.

[Sample No. 2A]

A light-emitting element was manufactured in the same manner as in the above-mentioned sample number 1A except that a silane coupling agent represented by the following chemical formula 4 was used in the above-mentioned step (3A).

[chemical formula 4]

[Sample No. 3A]

A light-emitting element was produced in the same manner as in the above-mentioned sample number 1A except that the above-mentioned step (3A) was omitted.

In addition, evaluations of luminous efficiency and lifetime were performed on the light-emitting elements of sample numbers 1A to 3A, respectively.

The evaluation of such luminous efficiency was carried out by applying a DC power supply voltage from 0 volts to 6 volts, measuring the current, and measuring the luminance with a luminance meter. In addition, the lifetime was evaluated by a constant current driving method with an initial luminance of 400 cd/m ² .

As a result, it was confirmed that the light-emitting elements of sample numbers 1A and 2A (invention) had increased luminous efficiency by about 1.3 times compared with the light-emitting element of sample number 3A (comparative example).

In addition, the light-emitting elements with sample numbers 1A and 2A (the present invention) had a half-life of luminance about 1.5 times longer than those of the light-emitting element with sample number 3A (comparative example).

In addition, the first organic polymer selected from polyarylamine, fluorene-arylamine copolymer or derivatives thereof is polymerized with the second organic polymer selected from polyfluorene, fluorene-bithiophene copolymer or derivatives thereof The same result can be obtained by combining the materials and manufacturing a light-emitting element in the same manner as above.

(Example 2)

Five evaluation objects were produced for each sample number as follows, and the separation state of each layer was confirmed, and the film thickness was measured.

[Sample No. 1B]

The same steps as the steps (1A) to (4A) in the above-mentioned sample number 1A were performed to prepare an evaluation object.

[Sample No. 2B]

The same steps as the steps (1A) to (4A) in the above-mentioned sample number 2A were performed to prepare an evaluation object.

[Sample No. 3B]

The same steps as the steps (1A) to (4A) in the above-mentioned sample number 3A were performed to prepare an evaluation object.

Furthermore, for the evaluation objects of sample numbers 1B to 3B, the separation state of each layer of the first region, the second region, and the light emitting layer was confirmed, and the film thickness was measured at the same time.

In this method, the first area, the second area, and the light-emitting layer were pulled off from the side of the light-emitting layer with a needle, and the peeled part was observed with a fluorescence microscope (manufactured by Olympus, "BX50"), and then measured with a height difference meter. (manufactured by KLA-Tencor, "P-10").

The measurement results of the film thickness of each layer are as follows. And the thickness value of each layer is the average value of five data.

Sample No. 1B (equivalent to the present invention)

The first area: 33 nm, the second area: 35 nm, the light emitting layer: 22 nm

Sample No. 2B (equivalent to the present invention)

First area: 35nm, second area: 34nm, light-emitting layer: 20nm

Sample No. 3B (equivalent to Comparative Example)

First area: 28nm, second area: 45nm, light-emitting layer: 18nm

For the evaluation objects with sample Nos. 1B and 2B, a clear height difference (step difference) was observed by fluorescence microscope observation, and each layer roughly formed the intended film thickness in the film thickness measurement results.

In contrast, for the evaluation object with sample No. 3B, although the height difference can be found by fluorescence microscope observation, the height difference is not obvious, and the measurement results of the film thickness have a large difference between each layer and the target film thickness. deviation.

These results indicate that more reliable phase separation can be achieved by performing an affinity-enhancing treatment. Furthermore, it is presumed that these results reflect the improvement in the characteristics of the light-emitting element shown in Example 1 above.

It was also confirmed that the separation state of each layer can be changed by changing the silane coupling agent for the affinity-improving treatment and producing an evaluation object in the same manner as above.

Claims (17)

1. A method of manufacturing a light-emitting element, comprising a light-emitting layer interposed between a pair of electrodes, and a carrier transport layer in contact with the light-emitting layer and composed of an organic polymer as a main material , characterized in that it has: a first process and a second process, wherein In the first step, of the pair of electrodes, an affinity improving treatment for improving affinity with the organic polymer is performed on a side where the carrier transport layer is formed on one electrode. ; In the second step, a liquid material containing the light-emitting layer constituent material, the organic polymer, and a liquid medium is supplied to the side of the carrier transport layer forming surface of the one electrode to form a liquid Formed film, while removing the liquid medium from the liquid film, the organic polymer is separated on the one electrode side, and the light-emitting layer constituent material is separated on the other electrode side to form together The carrier transport layer and the light emitting layer. 2. The method of manufacturing a light-emitting element according to claim 1, wherein the affinity-improving treatment in the first step is performed on the formation surface side of the carrier transport layer of the one electrode. , introducing a chemical modification process including a chemical structure of a part of the compounds constituting the organic polymer. 3. The method of manufacturing a light-emitting element according to claim 1 or 2, wherein the carrier transport layer is a hole transport layer. 4. The manufacturing method of the light-emitting element according to claim 3, wherein The hole transport layer has: on the side of the one electrode, a first region mainly composed of a first organic polymer; a second region composed primarily of a different second organic polymer; In the affinity improving treatment in the first step, a treatment for improving affinity with the first organic polymer is performed on the side of the light-emitting layer-forming surface of the one electrode. 5. The method of manufacturing a light-emitting element according to claim 4, wherein in the second step, the first region and the second region are formed together with the light-emitting layer by phase separation. 6. The method for manufacturing a light-emitting element according to claim 4 or 5, wherein the weight average molecular weight of the first organic polymer is larger than the weight average molecular weight of the second organic polymer. 7. The method for manufacturing a light-emitting element according to claim 6, wherein the first organic polymer has a weight average molecular weight of 10,000 or more. 8. The method for producing a light-emitting element according to claim 6 or 7, wherein the second organic polymer has a weight average molecular weight of 8,000 or less. 9. The method for producing a light-emitting element according to any one of claims 4 to 8, wherein the first organic polymer is polyarylamine, a fluorene-arylamine copolymer, or a derivative thereof. 10. The method for producing a light-emitting element according to any one of claims 4 to 9, wherein the second organic polymer is polyfluorene, a fluorene-bithiophene copolymer, or a derivative thereof. 11. The method for manufacturing a light-emitting element according to any one of claims 3 to 10, wherein the light-emitting layer is mainly composed of a composite material of an inorganic semiconductor material and a light-emitting material. 12. The method for producing a light-emitting element according to claim 11, wherein in the second step, the liquid solvent is removed in an atmosphere containing a polar solvent vapor. 13. The method for producing a light-emitting element according to claim 1 , wherein in the second step, the liquid solvent is removed while causing convection in the liquid film. . 14. The method of manufacturing a light-emitting element according to claim 13, wherein the convection is generated by heating the liquid coating. 15. A light-emitting element produced by the method for producing a light-emitting element according to any one of claims 1 to 14. 16. A display device comprising the light-emitting element according to claim 15. 17. An electronic device comprising the display device according to claim 16.

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